This video is about using the new adjustment layers panel and the new masking panel in Photoshop CS4. You can still work with adjustments and masks the same way you did in CS3, but there are also some new options and abilities that you are going to love.

I also had the same problem as jonathan hill. The whole picture changed, even the selection from the mask. Only what I selected with the quick mask mode was supposed to change, but the entire picture did. And when I got to the part where I change only the eyes vibrancy, it would make the whole picture saturated, not just the eyes. I re-watched the entire tutorial again to see what I did wrong, because I was following every exact thing you did, but still had problems. I did notice that on the layers menu, the masked selection was black instead of white. Yours was white and black, unlike mine. I did everything the same, yet the main difference were the colors. Could you please explain why the colors were opposite?

The reason it happened, because your selected everything else but the eye. When you add adjustment layer while selection is active, it creates layer mask revealing everything that’s selected, and hides everything that is not. If you look at masks thumbnail, black hides, white reveals, everything between black and white is transparent.
If you want change the effect of quick mask mode, just double click it’s thumbnail on toolbox, which opens quick mask options window. In this case select color indicates: selected areas.
After exiting from quick mask mode you’ll see your selection. If borders of document window has dotted line going all around it means you have selected everything else but the object you were painting on in quick mask mode. Just inverse the selection by going to Select menu and choosing Inverse or just use shortcut CTRL+SHIFT+I.
If you already added Adjustment layer and seeing different results than expected. To open a full view of layer mask in document window, Click ALT+left mouse button on layer mask thumbnail in Layers panel. Check your layer mask and see what’s white and what’s black. If your targeted object is covered in black in layer mask, go to Masks panel (make sure you select layer mask by clicking on thumbnail in layers panel) and press on Invert or just use keyboard shortcut CTRL+I.